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Mold Growth on Window Sills: Causes and Prevention

The presence of mold on window sills can cause many problems, including stains and compromised window life span. It can also trigger allergies and other respiratory illnesses. In this blog, local window and door replacement company  Renewal by Andersen® of Southwest Missouri shares a look at the things that you can do to prevent mold growth on window sills.Mold Growth on Window Sills: Causes and Prevention
What Causes Mold Growth on Window Sills?

High moisture levels are conducive to mold growth, which is why it thrives in humid areas such as basements, bathrooms, and attics. Moisture that comes from indoor condensation and humid outside air usually collect at the window sill, and doesn’t immediately dry out.

Exposed wood may also absorb and retain moisture. Sometimes these areas are blocked by window treatments, which would then allow mold to grow undisturbed and hidden from view. Certain types of mold, particularly black mold, are notoriously difficult to remove, even on the best vinyl replacement windows on the market.

The Effects of Mold

We have mentioned how the presence of mold can affect the respiratory system in both children and adults. To elaborate, some people have sensitivity to mold spores, and may develop stuffy nose, coughing, and throat irritation when exposed to high levels mold spores in the air. Skin and eye irritation may accompany these symptoms. Certain types of allergies may also be triggered by mold. A 2004 study conducted by the Institute of Medicine presents evidence that links exposure to mold indoors with asthma, hypersensitivity pneumonitis, and other upper respiratory problems.

How to Prevent Mold Growth on Window Sills

While you can’t completely eliminate mold spores from getting into your home, there are some things that you can do to prevent mold growth on window sills, as well as in other parts of your home:

Maintain Relative Indoor Humidity — Humidity levels change depending on the season: it’s dry during winter and humid during summer. A home humidifier/dehumidifier helps maintain indoor humidity relative to outdoor levels by releasing or absorbing moisture as needed, preventing window condensation and other issues that can lead to mold growth.

Allow Regular Ventilation — Opening your windows for at least 15 minutes a day helps flush out indoor air pollutants, including mold spores. You should also make sure that the air filters in your home ventilation system are replaced when full.

Regularly Clean Your Windows — Make it a point to clean your windows twice a year. Low-maintenance windows with easy cleaning features such as removable or tiltable sashes make this task easier and safer. Make sure that the window treatments are likewise cleaned.

Renewal by Andersen of Southwest Missouri is your leading provider of popular window styles, including double hung replacement windows. Give us a call at (417) 268-9301 or fill out our contact form to schedule an appointment.


"Great workmanship on windows installation is done very professionally by excellent crew. Installed in a very timely manner. Excellent company to deal with."

Roy D
Feb 14, 2023

"The Springfield team was wonderful to work with , professional , friendly and knowledgeable. They all seem to take great pride in their work. These new windows are fantastic, they look great , operate so easy and the energy efficiency was noticeable from the very first day . Thank you Renewal by Andersen for transforming our home and our lives."

Pam S
Feb 15, 2023

"After years of watching the wind move my drapes and hours of difficult cleaning, I decided to get new windows. I went with Renewal by Andersen because of the great reviews and quality. From Brent who did the consult, Gideon who did the measuring, to Jason, Josh, and I apologize I can't remember the third installers name, this is the most professional company I've ever worked with. I own a 1994 double wide mobile home, so everything in this place is hard to work with. I had a bay window, 6 double hung, 2 awning, and a front door replaced.. They said it would take 2 days and they were done on time! I did have second thoughts about doing this mainly because of the cost, but once it was done, I was very happy I did this."

Gary S
Feb 18, 2023

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